Internal browning control in ‘Laetitia’ plums by modified atmosphere, management of ethylene and storage temperature

Abstract The objective of this study was to evaluate the effect of modified atmosphere (MA) and 1-methylcyclopropene (1-MCP) treatment on low storage temperature (1.5 °C) and 1-MCP treatment on high storage temperature (8.0 °C) on fruit quality of ‘Laetitia’ plums, mainly on internal browning. The treatments evaluated were 1.5 °C; 1-MCP (1.0 µL L-1) + 1.5 °C; MA + 1.5 °C; 1-MCP + MA + 1.5 °C; 8.0 °C; 1-MCP + 8.0 °C. Fruit were stored for 30 and 40 days, followed by three day of shelf life. For fruit stored at 1.5 °C, the treatment with 1-MCP associated to MA provided higher flesh firmness, less intense skin red color and reduced occurrence of internal browning in comparison to the fruit stored at 1.5 °C of the remaining treatments, for both periods of storage. In fruit not treated with 1-MCP and stored at 8.0 °C there was no occurrence of internal browning, despite of lower flesh firmness and more intense red color of the skin and flesh in comparison to the fruit stored at 1.5 °C. The treatment with 1-MCP in fruit stored at 8.0 °C delayed those changes of flesh firmness and red color of the skin and flesh assessed after 30 days of storage, followed by three days of shelf life. The MA, regardless of 1-MCP treatment, had fruit with higher production of acetaldehyde after 30 days of storage, and ethanol after 30 and 40 days of storage at 1.5 oC. In fruit stored at 1.5 °C without MA, the treatment with 1-MCP reduced the production of ethyl acetate, acetaldehyde and ethanol. Fruit stored at 8.0 °C, regardless of 1-MCP treatment, had the lowest production of acetaldehyde and ethanol.

摘要 本研究旨在评估气调贮藏（modified atmosphere, MA）与1-甲基环丙烯（1-methylcyclopropene, 1-MCP）处理在1.5℃低温贮藏条件下的效果，以及1-MCP处理在8.0℃高温贮藏条件下对‘Laetitia’李果实品质的影响，重点关注内部褐变情况。本试验设置的处理组包括：1.5℃贮藏；1-MCP（1.0 µL L⁻¹）+1.5℃贮藏；MA+1.5℃贮藏；1-MCP+MA+1.5℃贮藏；8.0℃贮藏；1-MCP+8.0℃贮藏。所有果实分别贮藏30天与40天，随后置于货架环境中放置3天。针对1.5℃贮藏的果实，与其余同温度下的处理组相比，联合使用1-MCP与MA的处理组在两个贮藏周期下均表现出更高的果肉硬度、更浅的果皮红色色泽，且内部褐变发生率更低。未施加1-MCP且在8.0℃下贮藏的果实未出现内部褐变现象，但相较于1.5℃贮藏的果实，其果肉硬度更低，果皮与果肉的红色色泽更浓郁。对8.0℃贮藏的果实施加1-MCP处理，可延缓贮藏30天并经3天货架期后出现的果肉硬度、果皮与果肉红色色泽的变化。在1.5℃贮藏条件下，无论是否施加1-MCP处理，采用MA贮藏的果实在贮藏30天后乙醛生成量更高，且在贮藏30天与40天后乙醇生成量均更高。在1.5℃且未采用MA贮藏的果实中，1-MCP处理可降低乙酸乙酯、乙醛与乙醇的生成量。无论是否施加1-MCP处理，8.0℃贮藏的果实乙醛与乙醇生成量均为最低。